Wilderness Concepts

1)Somehow I have to tell him that I am missing 4 hrs of it for volleyball tryouts>
>>How do I tell him?> In the survival guide he wrote" you are a disgrace if you are late" and " if you miss, you're a waste of time because it slows everyone down"

But since this is mandatory I still want a spot on the line for marching/football season!

2)Also I am a person who does not take constructive critisism or any critisism at all well which apparently is his specialty, so how do I metally prepare myself for that?

3)One more thing, I hate playing alone or solo in front of my peers.
what is a good way to get over that?